CenterPoint Mapping/Monitoring Car?

I was out walking my dog last night around 10pm in a residential neighborhood inside the beltway and I noticed a CenterPoint car with hazards on driving down the street multiple times with a apparatus on top. Normally I would of thought this was a mapping exercise like I have seen with google and others but it was dark, also the guy hit the same spots a couple of times.. I didn't manage to get a pic of the car but I found it odd…. anyone know what this might of been after dark?